gastrocnemius

gas·troc·ne·mi·us (mus·cle)

[TA]

superficial muscle of posterior (plantar flexor) compartment of leg; origin, by two heads (lateral and medial) from the lateral and medial condyles of the femur; insertion, with soleus by tendo calcaneus into lower half of posterior surface of calcaneus; action, plantar flexion of foot; nerve supply, tibial.

gastrocnemius

/gas·troc·ne·mi·us/ (gas″tro-ne´me-әs) (gas″trok-ne´me-us) see under muscle.

gastrocnemius

(găs′trŏk-nē′mē-əs, găs′trə-)

n.pl.gastrocne·mii(-mē-ī′)

The largest, most prominent muscle of the calf of the leg, the action of which extends the foot and bends the knee.

gastrocnemius

[gas′trōnē′me·us]

Etymology: Gk, gastroknemia, calf of the leg

the most superficial calf muscle in the posterior part of the leg. It joins the tendon of the soleus as part of the tendo calcaneus. It flexes the leg and plantarflexes the foot. Compare plantaris,soleus.

Gastrocnemius

gas·troc·ne·mi·us mus·cle

(gas'trok-nē'mē-ŭs mŭs'ĕl)

Origin, by two heads (lateral and medial) from the lateral and medial condyles of the femur; insertion, with soleus by tendo calcaneus into lower half of posterior surface of calcaneus; action, plantar flexion of foot; nerve supply, tibial. Synonym(s): musculus gastrocnemius [TA] , gastrocnemius.

gastrocnemius

The main muscle forming the bulge of the calf. The gastrocnemius arises by two heads from the back of the lower end of the thigh bone (femur) and is inserted, with the SOLEUS muscle, by way of the ACHILLES TENDON into the back of the heel bone (CALCANEUS). Its action is to extend the ankle joint in walking and standing on tiptoe.

gastrocnemius

the largest muscle of the calf in the human leg.

Figure 1: The autonomic nervous system. Actions on the heart and on smooth muscle. Sympathetic actions on the left and parasympathetic actions on the right. Solid arrows: stimulation (contraction or secretion); broken arrows: inhibition.

gastrocnemius

the most superficial of the muscles of the back of the lower leg. It arises from the medial and lateral femoral condyles by two heads which join to form the inferior border of the popliteal fossa behind the knee. Together with its smaller accessory, the plantaris, and the soleus muscle (arising from the shaft of the tibia), it converges onto the Achilles tendon, to be inserted into the middle of the back of the calcaneum. It acts to plantarflex the foot and raise the heel when walking. Gastrocnemius and plantaris also act as weak flexors at the knee. SeeFigure 1.

gastrocnemius

large, two-headed muscle within the superficial part of posterior compartment of the lower leg (seeTable 1, Table 2andTable 3)

Anterior upper femur and tendon of adductor magnusAnterior and lateral surfaces of body of femurGreater trochanter and linea aspera of femurLinea asperaLateral condyle of femur

Superior and medial surfaces of patella and capsule of knee jointSuperior surface of patella and suprapatellar bursaSuperior and lateral surfaces of patella and capsule of knee jointHead of fibulaPosterior surface of upper tibia

Lateral surface of upper two-thirds of lateral fibulaLateral surface of lower two-thirds of lateral fibulaLateral surface of upper one-half of tibia and local interosseous membraneUpper one-half of tibia, fibula and local interosseous membraneAnterior surface of distal one-quarter of fibula

Base of first metatarsal and lateral side of medial (first) cuneiformBase of fifth metatarsalBase of first metatarsal and inferomedial aspect of medial (first) cuneiformMedial (first) cuneiform, inferior aspects of all tarsal bones (except the talus) and bases of second, third and fourth metatarsalsDorsal shaft of fifth metatarsal

Superior and anterior surfaces of the calcaneumMedial process of calcaneal tuberosityPlantar, medial and lateral aspects of calcaneumMedial process of calcaneal tuberosity and flexor retinaculumCalcaneal tuberosity

Dorsum of proximal phalanx of hallux, and extensor expansions of toes 2-4Plantar, middle phalanges of toes 2-5Tendon flexor digitorum longusMedial side of proximal phalanx of halluxLateral side of proximal phalanx of fifth toe

Lateral side of toes 2-4 and medial side toe 2Medial sides of bases of proximal phalanges of toes 3-5Extensor expansions toes 2-5Medial and lateral sides of base of proximal phalanx of halluxLateral side of base of proximal side of halluxLateral side of base of proximal phalanx of toe 5

Table 2: Movements occurring about the joints of the lower limb and foot

Note: Primary action of muscles is printed in normal type; muscles that give some contribution to this action are printed in italics .

The nerve supply to the lower limb (lower leg and foot) is derived from the sciatic and femoral nerves. Dysfunction or compromise of either of these nerves causes marked motor, sensory and autonomic effects in the lower leg and foot.

MTPJ, metatarsophalangeal joint; IPJ, interphalangeal joint.

Table 3: Presentations of osteochondritis/osteochondrosis in the leg and foot

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